Write each polynomial in standard form What is the name of the polynomial based on its degree and number of terms a 3 + 5x - 4x2
b. 8x + x + 5 + x3

A .
a 3 + 5x - 4x? quadratic trinomial
b 5 + 9x + x quadratic trinomial
B.
a -4x2 + 5x + 3. quadratic trinomial
b x + 9x + 5, cubic trinomial
C.
a.3 + 5x - 4x2 cubic trinomial
b.5+ 9x + x, cubic trinomial
D.
a -4x2 + 5x + 3. cubic trinomial
b x? + 9x + 5. quadratic trinomial

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?

An annual marathon covers a route that has a distance of approximately 26 miles. winning times for this marathon are all over 2 hours. the following data are the minutes over 2 hours for the winning male runners over two periods of 20 years each. earlier period 14 12 15 22 13 10 19 13 9 14 20 18 16 20 23 12 18 17 6 13 recent period 7 11 7 14 8 9 11 14 8 7 9 8 7 9 9 9 9 8 10 8 (a) make a stem-and-leaf display for the minutes over 2 hours of the winning times for the earlier period. use two lines per stem. (use the tens digit as the stem and the ones digit as the leaf. enter none in any unused answer blanks. for more details, view how to split a stem.) minutes beyond 2 hours earlier period 0 1 2 (b) make a stem-and-leaf display for the minutes over 2 hours of the winning times for the recent period. use two lines per stem. (use the tens digit as the stem and the ones digit as the leaf. enter none in any unused answer blanks.) minutes beyond 2 hours recent period (c) compare the two distributions. how many times under 15 minutes are in each distribution